----- Original Message -----
From: "Gregg Allen" <[EMAIL PROTECTED]>
.
.
This is what I was using for medians:
use Algorithm::MedianSelect::XS qw(median);
Aaah ... the following script demonstrates the Inline::C equivalent of that
function. It should work just as quickly and correctly as the function in
that module:
--------------------
use warnings;
use Inline C => <<'EOC';
void median(SV * x, ...) {
Inline_Stack_Vars;
long buffer, numbers[items];
int i, is_sorted, median;
if (Inline_Stack_Items <= 1) {
croak("Require more than one argument");
}
for (i = 0; i < items; i++) {
numbers[i] = SvIV(Inline_Stack_Item(i));
}
do {
is_sorted = 1;
for (i = 0; i < (Inline_Stack_Items-1); i++) {
if (numbers[i-1] < numbers[i] && numbers[i] < numbers[i+1])
continue;
if (numbers[i] > numbers[i+1]) {
buffer = numbers[i];
numbers[i] = numbers[i+1];
numbers[i+1] = buffer;
is_sorted = 0;
}
}
} while (!is_sorted);
if (Inline_Stack_Items % 2 == 0) median = Inline_Stack_Items / 2;
else median = (Inline_Stack_Items - 1) / 2;
Inline_Stack_Reset;
Inline_Stack_Push(sv_2mortal(newSViv(numbers[median])));
Inline_Stack_Done;
Inline_Stack_Return(1);
}
EOC
@x = (1106, 102, 103, 105, 104, 80, 1107);
$median = median(@x);
print $median, "\n";
-------------------------
Be warned, however, that it's Fridy evenin' over here .... I've had a few to
drink ... and my judgement may be impaired.
(My level of intelligence may also be impaired ... but that's *always* the
case ... irrespective of my level of sobriety :-)
You might gain a small (but measurable) performance in improvement if you
assign Inline_Stack_Items to a variable. (Haven't checked that .. and even
if it *is* the case, it's probably only measurable for very large arrays.)
Cheers,
Rob
